Grinding mills are typically used in mineral processing to grind mineral ore particles into smaller sized particles to facilitate further downstream processing, such as separation of the valuable mineral particles from unwanted gangue. The grinding mill typically has a lining to protect the inner surface of the mill body from damage during the grinding process. The lining is made up of several lining components, that are called ‘liners’, joined together to cover the inner surface of the mill body. The lining absorbs the impacts from the grinding media and particulate material being ground and so must be replaced once it is worn out or significantly damaged. This involves dismantling the lining into individual liners and then replacing the worn liners with new liners.
The installation and replacement of liners for grinding mills is a dangerous activity, taking place in a confined space and involving heavy pieces of equipment since liners can range from 50 kg up to many tonnes. Liner handling machines have been developed to improve worker safety in performing these tasks of installation and replacement. Conventional liner handling machines comprise a thick, solid main beam on which a conveying device delivers new liners along an upper side of the main beam along its length through an opening within an end of the grinding mill body. In operation, the main beam of the conventional liner handling machine is inserted through the opening of the grinding mill body into the grinding mill interior so as to minimise the amount manual handling of the liners by a worker. Cranes at either end of the main beam also allow lifting the liners to further reduce manual handling by workers, thus reducing the risk of injury. Thus, the liner handling machine enables the transport of liners from outside the grinding mill body into the inside of the grinding mill body, and vice-versa.
A problem with the state of the art liner handling machine is that the typical smallest main beam, being a beam around 400 mm deep and 600 mm wide, occupies a substantial cross-sectional area of the opening of the grinding mill body, which for example in a small grinding mill tends to be around 1450 mm to 1750 mm wide in diameter. Consequently, there is a limit as to the size of the liners that can be transported into the grinding mill body. Where grinding mills are of smaller capacity, the conventional liner handling machine cannot be used at all, as none of the liners can fit into the reduced opening of the grinding mill body caused by the main beam extending through the opening.
It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.